Talk:Maxwell's demon

The "Comparison to Feynman's Ratchet" section

This section is pretty confusing, and is nowhere near adequately sourced. It may or may not be a good analysis of Feynman's ratchet as a Maxwell's demon, but it looks like either WP:ORIGINAL RESEARCH or WP:SYNTHESIS. Everything on Wikipedia, each fact, has to be WP:VERIFIABLE from a reliable source. Nor are Wikipedia articles allowed to "synthesize" conclusions from different sources. Whole paragraphs of this section are unsourced. Another thing is that the section discusses the ratchet in terms of chemical bonds, and I don't see that in the sources. Also, the Jarzynski paper, besides having no evidence it was published anywhere but on Arxiv, analyzes a discrete "model" of the Feynman ratchet consisting of a particle on a lattice, not the ratchet itself. This essay might be more appropriate on Wikibooks, where original research is allowed. --Chetvorno^TALK 20:28, 19 November 2014 (UTC)

Deleted it. --Chetvorno^TALK 02:02, 29 December 2014 (UTC)

I think the opening sentence is misleading

The opening sentence says that Maxwell's Demon "shows that the Second Law of Thermodynamics has only a statistical certainty." I really dislike this phrasing and I think it will cause readers to get the wrong impression. The fact is that Maxwell's Demon, as invented, will always violate the 2nd Law. There is no statistics about it. It's not like the Demon sometimes violates the 2nd Law, but on average obeys it. I'd like to remove this quotation from the opening sentence, but I thought I'd open it up for discussion first because it would be a major change. Let me know what you think. Tedsanders (talk) 18:16, 8 June 2015 (UTC)

I agree, that "statistical" phrase has always bothered me, too. --Chetvorno^TALK 20:08, 8 June 2015 (UTC)

However, I think the current lead sentence

"...Maxwell's demon is a thought experiment created by the physicist James Clerk Maxwell to show that the Second Law of Thermodynamics can be violated."

is too strong; it contradicts the body of the article and needs some modification. It is not clear to me whether Maxwell actually believed the 2nd Law could be violated (this would be a revolutionary stand in the 1800s) or whether he invented his demon to clarify its workings. Even if he did, it is important to make clear to general readers that the 2nd law has survived. Although research into Maxwell's Demon has elucidated the working of the law, it has not shown that the 2nd Law can be violated in the sense that energy or temperature differences can be produced from a system at thermodynamic equilibrium. I think most modern physicists and sources would disagree with the lead sentence as it stands. What about something like: "...Maxwell's demon is a thought experiment created by the physicist James Clerk Maxwell which raises the question of whether the Second Law of Thermodynamics can be violated." --Chetvorno^TALK 05:00, 9 June 2015 (UTC)

I reverted the change, pending consensus on an appropriate revision. I also think that Maxwell's summary is too abstruse for the purpose of an encyclopedia article, and should be improved upon. My proposal:

"...Maxwell's demon is a thought experiment created by the physicist James Clerk Maxwell in which he suggested how the Second Law of Thermodynamics could hypothetically be violated."J-Wiki (talk) 18:18, 9 June 2015 (UTC)

That version would be fine with me. --Chetvorno^TALK 19:01, 9 June 2015 (UTC)

Great rewording! Thanks. (Also, sorry if my edit earlier was too unilateral. I wanted to discuss it first, but it looked like this talk page was pretty dormant, so I just decided to go ahead with it.) Tedsanders (talk) 19:23, 9 June 2015 (UTC)

No, you did the right thing; BRD. Glad someone had the guts to get rid of that "statistical" phrase; I didn't. --Chetvorno^TALK 20:09, 9 June 2015 (UTC)

"Feynman's thought experiment"

The first sentence of the 'Experimental work' section refers to "Feynman's thought experiment". Should 'Feynman' read 'Maxwell', here, or is this a reference to some other thought experiment by Feynman? If the latter, it ought to be described. --MichaelMaggs (talk) 13:31, 17 September 2015 (UTC)

It's a reference to Feynman's Brownian ratchet. Yeah, that term should be in there. Put it in. --Chetvorno^TALK 17:12, 17 September 2015 (UTC)

That makes more sense. Thanks. --MichaelMaggs (talk) 18:08, 17 September 2015 (UTC)

Biological systems

Happens in biology all the time, eg, gate proteins. And of course, the 2nd Law is never violated. 213.1.8.114 (talk) 02:03, 28 May 2016 (UTC)

Computer Daemons

The unsourced claim that computing daemons are named after Maxwell's demon is simply wrong. I am removing it. If anyone feels strongly enough to try to restore it, please find a citation. 69.255.61.212 (talk) 22:43, 1 May 2017 (UTC)